If you mean FIOS, then, IMO, it kicks the butt of Comcast, and I used to have Comcast. Comcast used to drop signal on me a couple times a week. So far, in my 3rd year of FIOS, not a single drop. Picture quality is at least eqaul to Comcast, IMO.
ETA: We use Netflix with no issues about 95% of the time. Sometimes during primetime it may stutter a tiny bit.